I. Field of the Invention
The present invention relates to a tripod assembly used for leveling of an imaging apparatus such as video cameras.
II. Background Art
In order to ensure stable panning and tilting of the imaging apparatus such as a video camera, it has been the general practice to use a level vial for adjusting the lengths of the legs of the tripod and performing the leveling of the imaging apparatus. Fine adjustment of the leg lengths is necessary for achieving an exact leveling of the imaging apparatus. In a case where a certain degree of leveling of the imaging apparatus is accomplished, it is cumbersome to adjust the lengths of the legs of the tripod each time a place to take picture is changed. In this connection, there is known a support such as disclosed in Published Japanese Translation of PCT Patent Application No. 2005-521844.
The support set forth in the above document is adapted to fix the imaging apparatus in a horizontal position independently of positioning of the tripod. The support comprises a pole/socket joint including a pole and a socket and disposed at an upper end portion of a pillar extending vertically. A tie rod for fixing the pole to the socket extends through the pillar and is operable by way of a knob disposed at a lower end portion of the pillar.
The above support is mounted on a base in a manner to be vertically movable relative to the base to which the upper ends of the legs of the tripod are pivotally coupled. The imaging apparatus is mounted on the pole via a fixing plate, a platform or the like, the pole being tilted relative to the socket so as to set the imaging apparatus in a horizontal position. Subsequently, the knob is manipulated to operate the tie rod for fixing the pole in position. Thus, the leveling of the imaging apparatus is accomplished. That is, the above support permits the leveling of the imaging apparatus to be performed independently of positioning of the tripod.
However, the knob for operating the tie rod is disposed at the lower end portion of the pillar, whereas the imaging apparatus is mounted to the pole disposed at the upper end portion of the pillar. Hence, an operation position to perform the operation of tilting the pole relative to the socket for setting the imaging apparatus to the horizontal position is at a different height from that of a position to perform the pole fixing operation. Further, the knob is located at a place downward from the base of the tripod. This forces a user performing the leveling operation to take improper postures. Accordingly, the leveling operation of the imaging apparatus is not always easy. In some cases, the user manipulating the knob may encounter an inadvertent pivotal motion of the pole caused by the weight or the like of the imaging apparatus set to the horizontal position. This leads to a problem that it takes much time and effort to achieve the exact leveling of the apparatus.
Furthermore, the tie rod and also a second pole/socket joint disposed at an upper end of the tie rod, in practice, are necessary for fixing the pole to the socket. Hence, all the supports may not have a simple structure, which reflects cost.
In view of the foregoing problems, the invention seeks to provide a low-cost tripod assembly facilitating the leveling operation of the imaging apparatus such as a video camera and having a simplified structure.